This project is a continuing study of the combined effects of iodide deficiency and protein deficiency on intellectual, neurological and physical development in a region of the Andes where endemic goiter is highly prevalent. The method of prophylaxis is iodized oil which is administered in the study regions of rural Peru and Ecuador in controlled mode. Effects are measured in terms of goiter and in growth and development of children. In addition, in the Ecuadorian study, supplements of lysine and tryptophane are given to pregnant and postpartem women as a supplement to their predominantly maize diet. This is done in double blind fashion. The children borne of these pregnancies are followed for growth and development.